# std::ranges::chunk_by_view<V,Pred>::find_next, std::ranges::chunk_by_view<V,Pred>::find_prev

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< cpp‎ | ranges‎ | chunk by view

## std::ranges::chunk_by_view::next

constexpr ranges::iterator_t<V> /*find-next*/( ranges::iterator_t<V> current ); |  | (since C++23) (exposition only*)

Finds the next chunk.

Let `base_` and `pred_` be appropriate underlying data-members of `chunk_by_view`.

Equivalent to

    return ranges::next
    (
        ranges::adjacent_find
        (
            current, ranges::end(base_), std::not_fn(std::ref(*pred_))
        ),
        1, ranges::end(base_)
    );

The behavior is undefined if pred_.has_value() is false before the call to this function.

Used in the following non-static member functions:

- ranges::chunk_by_view::iterator::`operator++`

### Parameters

current | - | the iterator to current element in adapted view

### Return value

An iterator to the next chunk, as described above.

## std::ranges::chunk_by_view::prev

constexpr ranges::iterator_t<V> /*find-prev*/( ranges::iterator_t<V> current ) requires ranges::bidirectional_range<V>; |  | (since C++23) (exposition only*)

Finds the previous chunk.

Let `base_` and `pred_` be appropriate underlying data-members of `chunk_by_view`.

Returns an iterator `i` in the range `[`ranges::begin(base_)`,` current`)` such that:

- ranges::adjacent_find(i, current, std::not_fn(std::ref(*pred_))) is equal to current, and
- if `i` is not equal to ranges::begin(base_), then bool(std::invoke(*pred_, *ranges::prev(i), *i)) is false.

The behavior is undefined if before the call to this function current == ranges::begin(base_) or pred_.has_value() != true.

Used in the following non-static member functions:

- ranges::chunk_by_view::iterator::`operator--`

### Parameters

current | - | the iterator to current element in adapted view

### Return value

An iterator to the previous chunk, as described above.

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